With GRAMOPHONE and RADIO

Radio Record, Volume III, Issue 32, 21 February 1930, Page 32

With GRAMOPHONE and RADIO

By

B Natural

Types of Needles and their Uses with Pick-ups

We are devoting our space this week wr the vital question of needles, and all owners of pick-ups whether used in connection with a gramophone combination or with the amplifier of their sets, will be interested. There is far more in selecting needles than there was with the. mechanical gramophone, where volume of sound only had to be considered. The accompanying article is non-technical and _ will appeal to all.

[8 the old days (we shall speak of them in these terms, although they are not yet really old), needles were grouped into three categories-loud, medium, and soft. There were a few other special groups such,as extra loud, spear point, special soft, etc., but these were relatively unimportant. The gramophone owner had merely to decide on the volume he required, and then select his needle accordingly. With the advent of the pick-up and the electric amplifier: volume could be easily controlled by a resistance in the pick-up (the volume control) or in the amplifier itself. If an amplifier requires different needles to discriminate in volume, then it is apparent that either the amplifier or the pick-up requires adjustment. In the modern apparatus the. function of

the: needle is tone, and aS modern tendeney in all musical reproduction is moving towards this, it is encumbent upon all who seek it with regard to gramophone reproduction, to find out the best type of needle to use. If every owner of a combination had special measuring instruments, the problem could be very simply solved, but as this is imposible, one must rely upon ear, The average person who has had some experience in listening to recorded music will have no difficulty in picking up the differences caused by changes in the needles. In very many ways the loud needle has been rendered old-fashioned. Loudness should be obtained by adjusting the volume control or the amplifier. The needle is fairly thick, and wear is rapid, so that before it has tracked out more than half the record, a surface has been worn which makes it a very blunt point. When it has gone to the inside of the record this definite face will be on the side nearest the spindle. If, as many unfortunately do, the needle is made to play again, it is returned to the outside and the face swung round so that a corner of it will tend to catch on the side of the groove, and ruin the record, This can be made

clear by reference to the diagram. The first figure shows a selection of a band record before it was played. The lower photograph shows the same record after it had been played fifty times. In these experiments care was taken with the needle, and even then a deep note, marked by the curve, was broken away at the edges. If now a_ sharp edge is brought into contact with those sides, the breaking away process will be very greatly accelerated and the records will be rapidly worn. This face is shown clearly in the small photo., where it is contrasted with a medium semi-per-manent needle on the right.

The medium needle is more _ suitable for gramophone reproduction. It gives an over-all brilliance, and the bass is well reproduced. A _ loud needle has a tendency towards greater emphasis in the treble, while a soft needle will strengthen the base to the detriment of the treble. The medium needle is then "the happy medium." Furthermore, the steel in it is much tougher, and the wear is not so great. Don’t rush to conclusions by this, and think that I am advocating that the medium needle should be used more than once. Not so. This can be as great a menace to records as is the loud needle when played twice--but more of this in a future article, when we shall discuss the care of records.

Reference to the same photograph reveals the fact that the wider .the needle the greater the wear on the records, and, for this reason the soft needle is the most economical. The effect of a needle on the grooves ean be seen in the larger photo. Continued testing has convinced me that there is a vast difference in the tone of a soft needle and a loud needle. Personally I prefer the soft needle, but every user is recommended to try all three steel needles and to make his decision accordingly. A word must be said about fibre needles. From a point of view of

wear, they are vastly superior to any other, for they do not injure the record in the slightest. One can even afford to be a little careless with these needles, for if they happen to run out of their track the grooves will not be impaired, but as one cannot advocate edrelessness, the fibre needle eannot be recommended from. this point of view. It is slightly weaker in volume than a soft steel needle, while there are slight losses in tone in cerfy\in types of music, but for all that it Is a good needle to use. It can be repinted without injuring the record. ‘The point can be played usually fcar or five times, depending on the size of the record and the weight of the midk-up.

These needles are very thick, and will not fit into the ordinary pick-up. A special attachment may be necessary, or a very much simpler method of using them is to trim the sharp edges off the haJf away from the point. . Much more could be said about need- . les, but from the point of view of wear on records, this will have to be left for a future article.